/**
* \internal
* \brief Test averaging conversion in 12-bit mode using the DAC
*
* These values are then measured using the ADC on the pins that are connected
* to the DAC channel, and the results are compared and checked to see if they
* are within the acceptable average of values that passes the test.
*
* \param test Current test case.
*/
static void run_averaging_conversion_test(
const struct test_case *test)
{
int16_t volt_output;
int16_t volt_min, volt_max, volt_input;
/* ADC module configuration structure */
struct adc_config adc_conf;
/* ADC channel configuration structure */
struct adc_channel_config adcch_conf;
adc_disable(&ADCA);
/* Change resolution parameter to accept averaging */
adc_read_configuration(&ADCA, &adc_conf);
adc_set_conversion_parameters(&adc_conf, ADC_SIGN_ON, ADC_RES_MT12,
ADC_REF_VCC);
adc_write_configuration(&ADCA, &adc_conf);
/* Enable averaging */
adcch_read_configuration(&ADCA, ADC_CH0, &adcch_conf);
adcch_enable_averaging(&adcch_conf, ADC_SAMPNUM_1024X);
adcch_write_configuration(&ADCA, ADC_CH0, &adcch_conf);
adc_enable(&ADCA);
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
/* Check values */
for (volt_output = -CONV_MAX_VOLTAGE;
volt_output <= CONV_MAX_VOLTAGE;
volt_output += CONV_VOLTAGE_STEP) {
main_dac_output(volt_output);
/* first capture */
volt_input = main_adc_input();
volt_min = volt_max = volt_input;
/* several capture */
for (uint8_t i = 0; i < 5; i++) {
volt_input = main_adc_input();
if (volt_min > volt_input) {
volt_min = volt_input;
}
if (volt_max < volt_input) {
volt_max = volt_input;
}
}
test_assert_true(test,
(volt_max - volt_min) < CONF_TEST_ACCEPT_DELTA_AVERAGING,
"ADC result is not in acceptable stable range (Min %dmV, Max %dmV)",
volt_min, volt_max);
}
}
/**
* \brief Executes several ADC captures according to several DAC output
* This functions send a table with all conversions on STDIO output.
*
* \param values Values from ADC
*/
static void main_conversions(uint16_t values[])
{
int16_t volt_output;
for (volt_output = -CONV_MAX_VOLTAGE;
volt_output <= CONV_MAX_VOLTAGE;
volt_output += CONV_VOLTAGE_STEP) {
main_dac_output(volt_output);
*values++ = main_adc_input();
}
}
/**
* \brief Executes several ADC captures according to several DAC output
* This functions send a table with all conversions on STDIO output.
*/
static void main_conversions(void)
{
int16_t volt_output, volt_input;
printf("| ADC input | ADC res. | Delta |\n\r");
for (volt_output = -1800; volt_output <= 1800; volt_output += 600) {
main_dac_output(volt_output);
volt_input = main_adc_input();
printf("| %5d mV | %5d mV | %4d mV |\n\r", volt_output,
volt_input, volt_input - volt_output);
}
}
int main(void)
{
const usart_serial_options_t usart_serial_options = {
.baudrate = CONF_TEST_BAUDRATE,
.charlength = CONF_TEST_CHARLENGTH,
.paritytype = CONF_TEST_PARITY,
.stopbits = CONF_TEST_STOPBITS,
};
/* Usual initializations */
board_init();
sysclk_init();
sleepmgr_init();
irq_initialize_vectors();
cpu_irq_enable();
stdio_serial_init(CONF_TEST_USART, &usart_serial_options);
printf("\x0C\n\r-- ADC Calibration Example --\n\r");
printf("-- Compiled: %s %s --\n\r\n\r", __DATE__, __TIME__);
/* ADC initializations */
main_adc_init();
printf("Commands:\n\r");
printf("- key 'c' to enable correction\n\r");
printf("- key 'd' to disable correction\n\r");
main_adc_correction_stop();
while (1) {
if (usart_rx_is_complete(CONF_TEST_USART)) {
char key = getchar();
if (key == 'c') {
main_adc_correction_start();
}
if (key == 'd') {
main_adc_correction_stop();
}
}
printf(" %4d mV\r", main_adc_input());
}
}
/**
* \internal
* \brief Test standard conversion in 12-bit mode using the DAC
*
* These values are then measured using the ADC on the pins that are connected
* to the DAC channel, and the results are compared and checked to see if they
* are within the acceptable range of values that passes the test.
*
* \param test Current test case.
*/
static void run_standard_conversion_test(
const struct test_case *test)
{
int16_t volt_output;
int16_t volt_input;
uint16_t error;
for (volt_output = -CONV_MAX_VOLTAGE;
volt_output <= CONV_MAX_VOLTAGE;
volt_output += CONV_VOLTAGE_STEP) {
main_dac_output(volt_output);
volt_input = main_adc_input();
if (volt_output > volt_input) {
error = volt_output - volt_input;
} else {
error = volt_input - volt_output;
}
test_assert_true(test, error < CONF_TEST_ACCEPT_DELTA,
"ADC result is outside acceptable range (expected %d, captured %d)",
volt_output, volt_input);
}
}
/**
* \internal
* \brief Test correction conversion in 12-bit mode using the DAC
*
* These values are then measured using the ADC on the pins that are connected
* to the DAC channel, and the results are compared and checked to see if they
* are within the acceptable range of values that passes the test.
*
* \param test Current test case.
*/
static void run_correction_conversion_test(
const struct test_case *test)
{
int16_t volt_output;
int16_t volt_input;
uint16_t error;
/** Measures and enables offset and gain corrections */
/* ADC channel configuration structure */
struct adc_channel_config adcch_conf;
uint16_t offset_correction;
/* Expected value for gain correction at 1.9V
* expected_value = Max. range * 1.9V / (VCC / 1.6)
* Max. range = 12 bits signed = 11 bits unsigned
*/
const uint16_t expected_value
= ((1 << 11) * 1900UL) / (3300L * 1000L / 1600L);
/* Captured value for gain correction */
uint16_t captured_value;
/* DAC Output 0 Volt */
main_dac_output(0);
/* Capture value for 0 Volt */
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
offset_correction = adc_get_unsigned_result(&ADCA, ADC_CH0);
/* Enable offset correction */
adcch_read_configuration(&ADCA, ADC_CH0, &adcch_conf);
adcch_enable_correction(&adcch_conf, offset_correction, 1, 1);
adcch_write_configuration(&ADCA, ADC_CH0, &adcch_conf);
/* DAC Output 1.9 Volts */
main_dac_output(1900);
/* Capture value for 1.9 Volts */
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
adc_wait_for_interrupt_flag(&ADCA, ADC_CH0);
captured_value = adc_get_unsigned_result(&ADCA, ADC_CH0);
/* Enable offset & gain correction */
adcch_enable_correction(&adcch_conf, offset_correction, expected_value,
captured_value);
adcch_write_configuration(&ADCA, ADC_CH0, &adcch_conf);
/* Check values */
for (volt_output = -CONV_MAX_VOLTAGE;
volt_output <= CONV_MAX_VOLTAGE;
volt_output += CONV_VOLTAGE_STEP) {
main_dac_output(volt_output);
volt_input = main_adc_input();
if (volt_output > volt_input) {
error = volt_output - volt_input;
} else {
error = volt_input - volt_output;
}
test_assert_true(test,
error < CONF_TEST_ACCEPT_DELTA_CORRECTION,
"ADC result is outside acceptable range (expected %d, captured %d)",
volt_output, volt_input);
}
}
